Metallized components and surgical instruments

ABSTRACT

An apparatus and related methods are described. The apparatus is described that includes a structural metal element including a metallic foam layer. The apparatus also includes a second metal element and a nonmetallic spacer. The nonmetallic spacer arranged between the structural metal element and the second metal element, the metallic foam layer joined to the nonmetallic spacer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent application Ser. No. 15/630,888, now U.S. Pat. No. 10,625,083, which claims priority from U.S. Provisional Patent Application No. 62/355,193, filed on Jun. 27, 2016, and this application claims priority from U.S. Provisional Patent Application No. 62/587,374, filed on Nov. 16, 2017, all of which are hereby incorporated by reference in their entireties.

TECHNICAL FIELD

This disclosure relates generally to techniques for joining polymeric, ceramic, or ceramic-polymer composite components to another component.

BACKGROUND

In overmolding to create structural attachment between a polymeric, ceramic, or ceramic-polymer composite component and underlying component(s) within an assembly, it may be difficult to obtain an adequate bond. This is exacerbated when the overall assembly size is preferably as small as possible, since the overmold requires adding to the volume of the assembly. Overmolded component surfaces may have limited or no adhesion to the surfaces of the underlying component. This lack of adhesion between mating surfaces of an assembly including an overmolded component may limit the strength of the assembly compared to alternatives in which adjacent surfaces of components within an assembly are adhered to each other.

SUMMARY

An apparatus and related methods are described. The apparatus is described that includes a structural metal element including a metallic foam layer. The apparatus also includes a second metal element and a nonmetallic spacer. The nonmetallic spacer arranged between the structural metal element and the second metal element, the metallic foam layer joined to the nonmetallic spacer.

Other features and advantages of embodiments of the present invention will be apparent from the accompanying drawings and from the detailed description that follows.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements and in which:

FIGS. 1A and 1B illustrate components of an assembly according to an embodiment;

FIG. 2 illustrates a surgical instrument according to an embodiment;

FIGS. 3A and 3B illustrate views of a jaw member of a surgical instrument according to an embodiment; and

FIGS. 4A and 4B illustrate metallic foam according to some embodiments.

DETAILED DESCRIPTION

Manufacture techniques disclosed herein facilitate attachment surfaces on a nonmetallic component, such as a polymeric (e.g., plastic), ceramic, ceramic-polymer composite or glass component for attaching the nonmetallic component to a metal component, or another nonmetallic component. As one example, surfaces to be joined are metallized to provide a ‘tie’ layer so that alternative bonding methods can be used. For polymeric and ceramic components, the metallized layers can be created with sputtering, such as sputtering with chromium, nickel, and or copper. For metal components, sputtering or plating, such as nickel plating, can be used if needed to provide a metallized ‘tie’ layer suitable for joining. The metallized ‘tie’ layers can be joined with a variety of methods, including, for example, soldering, brazing, adhesive bonding (using an adhesive designed for metal to metal bonding), compression fusion welding, metal fusion bonding, such as gold fusion bonding, and other metal to metal joining techniques. The techniques disclosed herein may be particularly useful for joining plastic to plastic, ceramic to ceramic, ceramic to metal, ceramic to plastic and/or plastic to metal components for products exposed to harsh environments, such as medical applications.

When joining surfaces of components with at least one polymeric or ceramic surface, such as nonmetallic spacer 34 of assembly 44 as illustrated in FIGS. 1A and 1B, bonding directly to the polymeric or ceramic surface may result in poor adhesion. As disclosed herein, first applying a metallized tie layer to the polymeric or ceramic surface provides a different functional surface for an adhesive to bond to. In the case of bonding two polymeric or ceramic components together, both components may be selectively sputtered with a metallized tie layer so that a metal-to-metal adhesive may be applied to join the surfaces. Such metal-to-metal adhesive may provide good bonding to the metallized tie layers and provide improved adhesion as compared to conventional techniques for polymer to polymer, ceramic to ceramic, ceramic to plastic, ceramic to metal and/or plastic to metal bonding.

These techniques may facilitate attaching a formed (planer or non-planar) metal component to a nonmetallic component, such as a support structure, spacer or stand-off, although it could also be used to bond two nonmetallic components. The nonmetallic component can alternatively be formed using other known methods for example, stamping, laser cutting, machining, and extruding.

In the example of two nonmetallic components, the described surface preparation techniques may be applied to both of the nonmetallic surfaces being attached and bonded. For plastic to plastic, ceramic to ceramic or ceramic to plastic surface joining, metalized surfaces may be formed on both nonmetallic components to act as a different surface onto which the bond can occur. Bonding may occur by solder, brazing, Au bonding, adhesives, or other metal to metal bonding techniques.

Certain ceramics, ceramic-polymer composites and plastic resins in the polyamide family such as Zytel, Akromid, Amodel, and similar are difficult to bond to metals including bonding with adhesives. Difficulties in such bonding may occur when the surface is non-planer or has 3D curved surfaces that mate. The techniques disclosed herein may be particularly useful for bonding such ceramics, ceramic-polymer composites and plastic resins to metal, ceramic or polymeric components.

These techniques may be used to create medical, e.g., surgical, instruments, such as electrosurgical or ultrasonic instruments for sealing tissue. Due to improved surface adhesion of adjacent components, surgical instruments assembled using these techniques may be smaller and/or more robust than surgical instruments instead assembled using overmolding techniques.

FIGS. 1A-1B illustrate components of an assembly 44. FIGS. 1A-1B illustrate an assembly technique utilizing solder as the attachment method between the tie layers. In particular, FIG. 1A illustrates an exploded view of the components of assembly 44, whereas FIG. 1B illustrates a cross-sectional view of the attached components of assembly 44.

Assembly 44 includes metal component 30, nonmetallic spacer 34 and stainless steel component 38. As shown in FIG. 1B, metal component 30 and stainless steel component 38 include optional nickel plating layers 2, 4 on a surface to be joined with a nonmetallic spacer 34. According to some embodiments, a metallic foam can be integrated into or applied on a surface of the metal component 30 and stainless steel component 38 to be joined with the nonmetallic spacer 34. This is discussed in greater detail with respect to FIG. 3B. Likewise, nonmetallic spacer 34 includes metalized tie layers 6, 8 such as a chromium, copper, and/or nickel layer, as well as solder layers 10, 12 that can be pre-tinned or applied using other known methods, on the surfaces to be joined with metal component 30 and stainless steel component 38. For example, the metallized tie layers 10, 12 may be formed using electroplating, electroless plating, vacuum, deposition, sputtering of metal, and other techniques. Such solder layers 10, 12 may be a solder suitable for use on medical devices, such as Indalloy 121 (or similar). In alternative examples, in which adhesive joining the metallized surfaces is chosen in place of solder, then the solder layer 10, 12 is not needed. Stainless steel component 38 may include a plating layer 4, such as a nickel plating layer.

In some particular examples, assembly 44 may represent components within a medical instrument. In such examples, it may be important to electrically and/or thermally isolate stainless steel component 38 from metal component 30. For example, assembly 44 may represent a jaw member of a surgical instrument for sealing tissue, such as vessel sealing, including, but not limited to, electrothermal sealing and ultrasonic sealing. In such an example, stainless steel component 38 may represent an electrically and/or thermally conductive sealing member referred to as “a sealing plate” that may be heated or electrically charged to facilitate tissue sealing. In some such examples, the thickness of stainless steel component 38 may be about 0.010 inches. In the same or different examples, the thickness of metal component 30 may be about 0.025 inches. Electrically charging stainless steel component 38 may occur using high-frequency electrical signals, such as bipolar electrical signals. Thermally heating stainless steel component 38 may occur using ultrasonic signals, e.g., with a piezoelectric crystal (not shown) adjacent to stainless steel component 38.

Nonmetallic spacer 34 may function to electrically and/or thermally isolate stainless steel component 38 from metal component 30. Metal component 30 may represent a structural component of the jaw member configured to pivot and/or actuate in conjunction with another jaw component to facilitate gripping and manipulation of tissue. The other jaw component may likewise include an electrically conductive sealing member that combines with stainless steel component 38 to facilitate tissue sealing between the two jaw components.

Prior to metal-to-metal bonding techniques to bond metal component 30, nonmetallic spacer 34 and stainless steel component 38 together, the components should be properly aligned as desired for the final assembly. For solder attach bonding, the components may be stacked and aligned and baked to allow the pre-tinned low temp solder to reflow and wet to the metallized portions of the mating pieces. Generally, the solder should wet only to the metallized regions.

In glue attach bonding, (metallized to metallized), adhesive may be applied before stacking and aligning the components. The metallized faces provide an alternative to bonding directly to nonmetallic spacer 34 and may provide stronger adhesion that directly applying an adhesive to nonmetallic spacer 34.

As shown in FIG. 1B, metal component 30, nonmetallic spacer 34 and stainless steel component 38 may be joined by way metal-to-metal bonding techniques, such as solder or other techniques. In this manner, an overmold layer is not needed. The interface surfaces for a strong mechanical attachment provided by the metalized tie layer on nonmetallic spacer 34 allows nonmetallic spacer 34 to be joined using metal joining techniques to other components, such as metal component 30 and stainless steel component 38. These techniques eliminate the need for an overmold.

Assembly 44 provides sealing between metal component 30, nonmetallic spacer 34 and stainless steel component 38. For this reason, in a bending type loading applied to assembly 44, the three layers, i.e., metal component 30, nonmetallic spacer 34 and stainless steel component 38, reinforce each other to provide additional bending strength than with what may be achieved with conventional overmolding.

In some particular examples, assembly 44 may represent components within a medical instrument. In such examples, it may be important to electrically and/or thermally isolate stainless steel component 38 from metal component 30. In some such examples, the thickness of stainless steel component 38 may be about 0.010 inches. In the same or different examples, the thickness of metal component 30 may be about 0.025 inches. Attachment surfaces of metal component 30 and stainless steel component 38 may be optionally nickel plated, chrome plated or plated with other materials to provide the proper tie layer interface. In addition, adjacent surfaces of nonmetallic spacer 34 may be metalized with a tie layer to facilitate bonding to metal component 30 and stainless steel component 38 using metal-to-metal joining techniques. Such metalized tie layers 6, 8 are optionally patterned. In some examples, nonmetallic spacer 34 may be a polymeric component, such as an injection molded fiber filled component, such as glass fiber or carbon fiber component, a ceramic component, or a blend of polymer and ceramic materials forming a composite component.

In a variation of assembly 44, a high strength nonmetallic may be added instead of or in addition to metal component 30 in order to provide structural strength to the assembly. In another variation, the function of metal component 30 and nonmetallic spacer 34 may be replaced by a single high strength nonmetallic component layer.

In a further variation of assembly 44, stainless steel component 38 may be replaced with an electroplated component on nonmetallic spacer 34 or directly on a high strength nonmetallic component layer. Such electroplating and/or electroforming may occur on a metalized tie layer of the nonmetallic component.

Following the formation of a metalized tie layer on the nonmetallic component, the surface of the nonmetallic component may be positioned to mate with a metallic surface of a second component. Then the metallized tie layer on the nonmetallic component may be joined with the mated metallic surface of the second component using metal to metal joining techniques.

The second component may be a metal component or a nonmetallic component with a second metallized tie layer on the second component. In different examples, metallized tie layers may be used for joining plastic to plastic, ceramic to ceramic, ceramic to metal, ceramic to plastic and/or plastic to metal components for products exposed to harsh environments, such as medical applications.

In accordance with the techniques disclosed herein, possible methods of metal-to-metal attachment of one or more nonmetallic components include, fusion of metal (welding), brazing, soldering, adhesive bonding, fusion of plated metals (e.g., via ultrasonics or resistance), or other metal-to-metal bonding techniques as discussed in further detail below.

As the properties of certain base materials, such as metallic components and non-metallic components may be affected at temperatures required for particular bonding techniques, metal-to-metal bonding techniques that do not require temperatures adverse to the base materials may be used. Generally speaking, bonding techniques rely on materially-compatible (wettable and having an ability to form a strong bond after wetting and cooling/solidification), pre-prepared substrate and bonding part surfaces that can readily adhere/bond to the molten metal bonding material.

In addition to the techniques listed above, low temperature melting nanoparticle material bonding techniques may be useful in some examples for joining plastic to plastic, ceramic to ceramic, ceramic to metal, ceramic to plastic and/or plastic to metal components. With low temperature melting nanoparticle material 1 bonding, a “nanoparticle” solder is used that achieves lower processing temperatures by using small particle sizes to fully melt the solder at temperatures the base material of component can handle.

As another example, low temperature and pressure sintering bonding techniques may be useful in some examples for joining plastic to plastic, ceramic to ceramic, ceramic to metal, ceramic to plastic and/or plastic to metal components. With low temperature and pressure sintering bonding, sintering mostly relies on partially melting a bonding material (such as softening/melting the surface of the particles to be sintered) and then applying pressure to form the high surface area strong bond with the components. Such techniques may use a low-temperature “nanoparticle” solder or other sintering materials.

As other examples, melting or reactive photonic curing or sintering bonding may be useful in some examples for joining plastic to plastic, ceramic to ceramic, ceramic to metal, ceramic to plastic and/or plastic to metal components. With melting or reactive photonic curing or sintering bonding, a “flashlamp melted” material may allow for maintaining low temperatures through ultra-fast heating and melting of the bonding material. The bonding material may absorb the flashlamp energy and simply melt or the bonding material may start an exothermic, self-sustaining reaction at the surface which may propagate across and through the film such that the film melts itself and wets and heats the surface of components to form a bond.

As other examples, low temperature and pressure reactive soldering/brazing material bonding may be useful in some examples for joining plastic to plastic, ceramic to ceramic, ceramic to metal, ceramic to plastic and/or plastic to metal components. With low temperature and pressure reactive soldering/brazing material bonding a molten compound formation, typically a eutectic compound, may be located between the metal bonding material and the substrate and component. Such techniques are distinct from those that rely upon a melting of only the bonding material which then wets to the components. The molten material for low temperature and pressure reactive soldering/brazing material bonding can be formed through the application of heat and pressure to get interdiffusion and start the eutectic compound formation, which then melts at the current temp. Alternatively or additionally, the molten material for low temperature and pressure reactive soldering/brazing material bonding can be formed by using multiple-component (mixtures of particles or multilayer films) bonding materials such that they melt and intermix due to an ignition event (such as an electric arc or laser heating at one tiny spot), then, due to high energy of mixing and self-propagating reaction, the entire bonding material melts and gives off enormous amounts of heat, which causes strong bond formation to the substrate and bonding part while maintaining low average/equilibrium temperature and minimizing the thermal effect on substrates.

Alternatives to non-conductive spacer concepts include:

-   -   Use of high performance board as the non-conductive spacer.         (Such as but not limited to Rogers LoPro R04000 series high         frequency laminates, available from Rogers Corporation of         Rogers, Conn., United States). This could be utilized as a         laminate (IE—pre clad with conductive layers), and/or it could         be an unclad core which is subsequently metallized by techniques         discussed above.     -   Use of powder coating as the non-conductive spacer.

EXAMPLES

Various embodiments of processing options for joining a nonmetallic surface to a metal surface, such as a joining of a nonmetallic surface to a non-planar (3D) metal surface, as shown in FIG. 1B, are described below. These examples are merely representative of the techniques disclosed herein and other techniques may be used within the spirit of this disclosure. Other non-planar metal surfaces that may be used include, but are not limited to, cylindrical or tubular structures such as, but not limited to, joining a metallic tube, rod, or wire to a non-metallic polymer tube.

Example 1

A nonmetallic component, such as a plastic, ceramic or plastic ceramic composite 3D component, is modified with an oxygen containing plasma using techniques including those known in the art. More specifically, a surface of a nonmetallic component may be modified using a plasma source containing oxygen, or argon or both prior to forming a metallized tie layer on the surface of the nonmetallic component. For another embodiment, a surface of a nonmetallic component is modified with an oxygen using an ion source containing oxygen, or argon or both prior to forming a metallized tie layer on the surface of the nonmetallic component. A surface of the nonmetallic component is then sputtered with chromium (Cr) to form a metalized tie layer to a subsequent solderable metal. For other embodiments, a metalized tie layer is formed by sputtering a metal including, but not limited to, titanium (Ti), tantalum (Ta), ruthenium (Ru), nickel-chrome (NiChrome), and nickel-vanadium (NiV). According to some embodiments, the metalized tie layer is deposited using a shadow mask. Yet other embodiments include using a vapor deposition to form a metalized tie layer. For various embodiments, the tie layer is from 50 angstrom to 500 angstroms thick. The tie layer is preferably 75 to 150 angstroms thick. The sputtered subsequent solderable metal is chosen from copper (Cu), nickel (Ni), gold (Au), platinum (Pt), palladium (Pd), silver (Ag), ruthenium (Ru), cadmium (Cd), Tin (Sn), radium (Ra), brass, etc. Other solderable metals may include one that forms an intermetallic without fully dissolving into a solder. Yet another solderable metal that could be used according to embodiments includes one that can be electroplated to a metallic surface of a component. The thickness of the solderable metal, according to some embodiments, may be greater than 500 angstroms and less than 50000 angstroms, such as greater than 1000 angstroms and less than 5000 angstroms.

Example 2

In this example, the techniques of Example 1 are repeated with the addition of compression bonding using gold as the bonding material and chrome as the tie layer.

Example 3

In this example, the techniques of Example 1 are repeated with mismatched metals such as nickel on one surface, Pd on another, or Au on one and nickel on the other, etc.

Example 4

In this example, the techniques of Example 1 are repeated using a nonmetallic component that is difficult to bond using adhesives such as polyamides, polytetraflourides, polydiflourides, etc.

Example 5

In this example, bonding two nonmetallic components are bonded together. Mating surfaces of both components are selectively sputtered with a metallized tie layer so that a metal-to-metal joining techniques, such as a metal-to-metal adhesive may be applied to join the surfaces. Such metal-to-metal adhesive may provide good bonding to the metallized tie layers and provide improved adhesion as compared to conventional techniques for plastic to plastic, ceramic to ceramic or ceramic to plastic bonding.

FIG. 2 illustrates a surgical instrument 100 configured to facilitate tissue sealing between sealing surfaces 103, 104 of mating jaw members 101, 102. Mating jaw members 101, 102 include arms 105, 106, which are rotatable relative to one another via pivot joint 107 to allow mating jaw members 101, 102 to open and close. According to the illustrated example, when mating jaw members 101, 102 are closed sealing surfaces 103, 104 are about parallel to one another. In other examples, arms 105, 106, may be rotatable relative to one another to allow mating jaw members 101, 102 to open and close via a different mechanical configuration, such as, for example, a four-bar linkage.

Jaw members 101, 102 may each be manufactured according to the techniques disclosed above with respect to assembly 44. According to various examples, surgical instrument 100 may be an electrosurgical instrument or an ultrasonic surgical component. In either example, the electrical or ultrasonic activation of sealplates 101, 102 heats sealplates 101, 102 to facilitate tissue sealing for tissues, such as vasculatures or other vessels, pinched between sealing surfaces 103, 104.

FIGS. 3A and 3B illustrate jaw member 102 in further detail according to some embodiments. In particular, FIG. 3A is a perspective view of jaw member 102, and FIG. 3B is a cross-sectional view of a portion of jaw member 102 including sealing surface 104. Jaw member 102 includes metal component 130, which represents a structural component of jaw member 102. Jaw member 102 also includes sealplate 138, which is heatable to facilitate tissue sealing with the corresponding sealplate of jaw member 101.

Nonmetallic spacer 134 is located between metal component 130 and sealplate 138. Nonmetallic spacer 134 functions to electrically and/or thermally isolate sealplate 138 from metal component 130. In different examples, nonmetallic spacer 134 may be a polymeric component, a ceramic component, a ceramic-polymer composite component, a resin plastic injection molded component, or another nonmetallic component.

Metal component 130 is configured to pivot and/or actuate in conjunction with the corresponding metal component of jaw member 103 to facilitate gripping and manipulation of tissue. In addition to gripping and manipulation of tissue with jaw members 102, 103, the electrical or ultrasonic activation of sealplates 101, 102 heats sealplates 101, 102 to facilitate tissue sealing for tissues, such as vasculatures or other vessels, pinched between sealing surfaces 103, 104.

In some examples, sealplates 101, 102 may be formed from stainless steel. The sealplates, according to various embodiments, may have a thickness in a range of about 0.0001 inches to about 0.02 inches. According to other embodiments, the thicknesses of sealplates 101, 102 may be about 0.010 inches. In the same or different examples, the thickness of metal component 130 may be about 0.025 inches. Electrically charging sealplates 101, 102 may occur using high-frequency electrical signals. Thermally heating sealplates 101, 102 may occur using ultrasonic signals, for example, with a piezoelectric crystal, adjacent to sealplates 101, 102.

Sealplate 102 includes sealplate spacers 142 on sealing surface 104. Sealplate spacers 142 are electrically and/or thermally insulating and function to provide a minimum predefined gap between sealing surfaces 103, 104 when mating jaw members 101, 102 are closed. The predefined gap, defined according to the thicknesses of sealplate spacers 142, may be selected to provide suitable tissue sealing. The gap between sealing surfaces 103, 104 can also prevent undesirable contact between sealing surfaces 103, 104. For example, contact between sealing surfaces 103, 104 may result in the welding of sealplates 101, 102 to one another, especially in examples in which sealplates 101, 102 are electrically activated. Sealplate spacers 142 may further serve to provide texture to sealing surfaces 103, 104, thereby increasing friction between sealing surfaces 103, 104 and tissue pinched between sealing surfaces 103, 104. The material of sealplate spacers 142 should be selected to withstand operating temperatures of sealplates 101, 102. In various examples, sealplate spacers 142 may be polymeric components, ceramic components, ceramic-polymer composite components, a resin plastic injection molded component, undoped silicon components, alumina-filled epoxy components and/or another nonmetallic component. For example, sealplate spacers 142 may be formed from undoped silicon wafers, e.g., via dicing or kiss-cutting. Sealplate spacers 142 may have thicknesses in the range of about 0.001 inches to about 0.02 inches.

Components of surgical instrument 100 include metallized tie layers 131, 133, 135, 137, 139, 143 to facilitate bonding to adjacent components using metal to metal bonding techniques for metal to metal joints 152, 154, 156. Metal to metal joints 152, 154, 156 may be created with a variety of methods, including, for example, soldering, brazing, adhesive bonding (using an adhesive designed for metal to metal bonding), compression fusion welding, metal fusion bonding, such as gold fusion bonding, and other metal to metal joining techniques. For an example using compression fusion welding, a surface of a nonmetallic component and a surface of a metallic surface are gold plated and the compression fusion weld is made by contacting the two gold plated surfaces and applying an energy source. Examples of an energy source include, but are not limited to, ultrasonic, megasonic, or other types of energy sources.

Metal component 130 includes metallized tie layer 131, which is bonded to metallized tie layer 133 of nonmetallic spacer 134 via metal to metal joint 152. Nonmetallic spacer 134 further includes metallized tie layer 135, which is bonded to optional metallized tie layer 137 of sealplate 138 via metal to metal joint 154. For example, optional metallized tie layer 137 of sealplate 138 may be sputtered or plated on the base metal of sealplate 138. In other examples, metallized tie layer 135 may be bonded directly to the base metal of sealplate 138 via metal to metal joint 154. Sealplate 138 further includes optional metallized tie layer 139, which is bonded to metallized tie layers 143 of sealplate spacers 142 via metal to metal joints 156. Optional metallized tie layer 139 may represent a continuous layer adjacent to more than one of sealplate spacers 142, such as all of sealplate spacers 142 or separate areas, each associated with an individual one of sealplate spacers 142. In other examples, metallized tie layers 143 of sealplate spacers 142 may be bonded directly to the base metal of sealplate 138 via metal to metal joints 156.

When joining surfaces of components with at least one polymeric or ceramic surface, such as nonmetallic spacer 34 of assembly 44 as illustrated in FIG. 1B, bonding directly to the polymeric or ceramic surface may result in poor adhesion. As disclosed herein, first applying a metallized tie layer to the polymeric or ceramic surface provides a different functional surface for an adhesive to bond to. In the case of bonding two polymeric or ceramic components together, both components may be selectively sputtered with a metallized tie layer so that a metal-to-metal adhesive may be applied to join the surfaces. Such metal-to-metal adhesive may provide good bonding to the metallized tie layers and provide improved adhesion as compared to conventional techniques for polymer to polymer, ceramic to ceramic, ceramic to plastic, ceramic to metal and/or plastic to metal bonding.

While jaw member 102 is described as including metal to metal joints 152, 154, 156, in some examples, jaw member 102 may include more or less metal to metal joints. For example, sealplate spacers 142 may be secured to sealplate 138 via metal to metal joints 156, while nonmetallic spacer 134 is an overmolded component without one or both of a metal to metal joints 152, 154.

While only jaw member 102 is described in detail, jaw member 101 is substantially similar to jaw member 102, except for the addition of nonmetallic sealplate spacers 142 on sealing surface 104 of sealplate 138 of jaw member 102. The exception is that jaw member 102 includes nonmetallic sealplate spacers 142 on the sealing surface 104 of sealplate 138. While according to the illustrated example, contrast jaw member 101 does not include nonmetallic sealplate spacers, in other examples, both of sealing surfaces 103, 104 may include nonmetallic sealplate spacers. Such nonmetallic sealplate spacers on both of sealing surfaces 103, 104 may be arranged such that some or all of opposing sealplate spacers on both of sealing surfaces 103, 104 to contact on another or staggered to avoid contact one another.

According to some embodiments, a metallic foam is used instead of metal to metal joints 152, 154, 156 with metallized tie layers 131, 133, 135, 137, 139, 143. For example, a metallic foam can be laser welded, soldered, or glued to the metal component 130 or the sealplate 138. According to other embodiments, the metallic foam is integrated into the metal component 130 forming a single component. As such, one side of the metal component 130 is fabricated to have the structure forming the metallic foam. Moreover, the metallic foam can be joined to a non-metallic structure, such as a polymeric (e.g., plastic), ceramic, ceramic-polymer composite or glass component for attaching the nonmetallic component to a metal component, or another nonmetallic component. Thus, according to some embodiments, the metallic foam can be attached directly to the nonmetallic spacer 134. The metallic foam can be joined to the nonmetallic spacer 134 by glue, injection molding, hot glue type attach, hot pressing, pressing, scrubbing or ultrasonic welding.

FIGS. 4A and 4B illustrate metallic foam 400 in further detail according to some embodiments. In particular, FIG. 4A is a cross-sectional view of a metallic foam 400, and FIG. 4B is a cross-sectional view of a metallic foam 400. The metallic foam 400 can be used as an interlayer to join two or more different structures such as bonding the seal plate 138 to the nonmetallic spacer 134. According to alternative embodiments, the metallic foam 400 can be the actual structure assembly 44.

As shown in FIGS. 4A and 4B, the metallic foam 400 can include a high porosity body structure. According to some embodiments, the metallic foam 400 can be fabricated and then formed/shaped into a complex three-dimensional shape, such as a honey-comb structure. According to some embodiments, the metallic foam 400 can be formed, and/or coined or compressed.

In this way, the metallic foam 400 is configured to be bonded to the metal component 130, the sealplate 138, and the nonmetallic spacer 134. The metallic foam 400 can be glued to the nonmetallic spacer 134 where the glue can lock into the honey-comb porous structure 401. In bonding the metallic foam 400 to the nonmetallic spacer 134 by injection molding, the flowing polymer locks into the honey-comb porous structure 401. In bonding the metallic foam 400 to the nonmetallic spacer 134 by hot glue attach, hot glue can flow and lock into the honey-comb porous structure 401. In bonding the metallic foam 400 to the nonmetallic spacer 134 by hot pressing, pressing, scrubbing/ultrasonic welding, the foam can be pressed into the nonmetallic spacer 134 (e.g., polymer) with pressure. The resulting pressure will cause the nonmetallic spacer 134 to deform into the honey-comb porous structure 401.

Although the disclosed techniques have been described with reference to various examples, those skilled in the art will recognize that changes can be made in form and detail without departing from the spirit and scope of this disclosure. 

What is claimed is:
 1. An apparatus comprising: a structural metal element including a metallic foam layer; a second metal element; and a nonmetallic spacer arranged between the structural metal element and the second metal element, the metallic foam layer joined to the nonmetallic spacer.
 2. The apparatus of claim 1, wherein the metallic foam layer is formed integral with the structural metal element.
 3. The apparatus of claim 2, wherein the metallic foam layer is a separate layer from the structural metal element and bonded to the structural metal element.
 4. The apparatus of claim 1 is a medical instrument.
 5. The apparatus of claim 4, wherein the medical instrument is a tissue sealing medical instrument, wherein the structural metal element, the second metal element, and the nonmetallic spacer form a jaw element of the tissue sealing medical instrument.
 6. The apparatus of claim 4, further comprising: a second nonmetallic spacer on an external surface of the second metal element; a second metallic foam layer on the second nonmetallic spacer; and a joint formed between the second metal element and the second nonmetallic spacer using the second metallic foam layer.
 7. The apparatus of claim 6, wherein the second nonmetallic spacer is one of a group consisting of: a polymeric component; a ceramic component; a ceramic-polymer composite component; a glass component; and an undoped silicon component; and an alumina-filled epoxy component.
 8. The apparatus of claim 6, wherein the medical instrument is a tissue sealing medical instrument, wherein the second metal element is a sealplate, and wherein the second nonmetallic spacer is a nonmetallic sealplate spacer is on an external surface of the sealplate.
 9. The apparatus of claim 6, wherein the second metallic foam layer is formed on the second nonmetallic spacer by at least one of: glue, injection molding, hot glue type attach, hot pressing, pressing, scrubbing, and ultrasonic welding.
 10. The apparatus of claim 6, wherein the second metallic foam layer includes a honey-comb structure.
 11. The apparatus of claim 1, wherein the metallic foam layer includes a honey-comb structure.
 12. The apparatus of claim 1, wherein the metallic foam layer is joined to the nonmetallic spacer by at least one of: glue, injection molding, hot glue type attach, hot pressing, pressing, scrubbing, and ultrasonic welding. 